| Acronym | Definition |
|---|
| HfSi | Hafnium Silicide |
| HfSi | Healthcare Fire Safety Instructors (California) |
| HfSi | Honeywell Federal Systems, Inc. (formerly) |
| HfSi | High Frequency Service Item |
| HfSi | Healthcare Financial Strategies, Inc. |
| HfSi | Hogan Financial Systems, Inc. |
| HfSi | Hardman Financial Services, Inc. |
| HfSi | Heart Failure Support Initiative |
| HfSi | Hawkeye Food Systems, Inc. |
| HfSi | Hawaii Family Support Institute |
| HfSi | High Frequency Service Indicator |
| HfSi | Healthy Fair-Skinned Infant |
| HfSi | Houses For Sale In (UK realestate web portals) |
| HfSi | Holy Family Service International (Houston, TX) |